The InFocus Short Throw Lens for IN42 and C445 enhances your projector's performance by helping to give you a clear, focused picture in any venue. It features a 20-31.9 mm focal lenth and f/1.9-2.5 aperture range. A 1:1.6 zoom ratio lets you get up close and 10.0 keystone correction helps to deliver a perfectly squared image at any angle. It's just one of the powerful tools offered by InFocus to get the best out of your projector. You can use it to enhance your business or educational presentations wherever you go, since the compact lens also travels easily and doesn't take up much space. A good lens could be the difference between making a good presentations and making a great one.